The Medical Information Bus (MIB) represents an application of networking and information technology for healthcare. The purpose of MIB is to define a standard means of connectivity between critical care bedside medical devices and hospital host computers. The devices include patient monitors, infusion pumps, ventilators, pulse oximeters and other devices used in operating rooms, intensive care units and emergency rooms.MIB addresses the unique needs of implementing data communications in the acute care environment. These challenges include: (1) the absolute need to guarantee patient, user and equipment safety; (2) the need for complete standardized plug-and-play operation with no user intervention; (3) the need to provide a framework for an expandable data language; and (4) the need to provide open system interoperability to hospital wide information systems.MIB is defined by the emerging family of ANSI/IEEE 1073 standards. The 1073 family follows the ISO OSI 7-layer model. The first two documents in this family, the 1073.3.1 Transport Profile and the 1073.4.1 Physical Layer for Cable Connected Devices define lower layer plug-and-play operation for a bedside subnetwork. They were approved as IEEE standards in December 1994; as ANSI standards in August 1995; and went out for ‘red cover’ pre-ballot procedure as CEN European standards in April 1998.The upper layer MIB standard documents utilize mOSI, a highly streamlined subset of the full OSI upper layers protocol, define optimized encoding rules, and the Medical Device Data Language (MDDL), an expandable framework based on object oriented technology. The MIB upper layer standards leverage a great deal of the work of the CEN VITAL committee in defining the information models and nomenclature for parameters, waves and alarms for specific device types. Future 1073 standards will define internetworking between local bedside data collection hubs and hospital wide networks.